Aaron Koblin knows the answer: It can be more than 19,000 in the United States. And thanks to his wizardry with FAA data, we can see how these aircraft drift from city to city in this mesmerizing computer visualization.

Air traffic is heavy in the early evening but hits a low of about 4,100 in-transit flights around 4 a.m. EST. It rockets upward again after the sun rises, peaking around 3 p.m. Take-offs flow in a wave across the country as people wake up and get to the airport. On the East Coast, flights shoot out of major hubs like New York City and Atlanta like the sparks of exploding fireworks, while solitary jets squirm around like protozoa in less-populous areas like Canada and the Gulf of Mexico.

Koblin, a graduate of UCLA who's worked in the gaming industry, created this wondrous map with the Processing programming tool, Adobe After Effects and the 3-D animation aid Maya. The visualization does not include a date for his data set, but an earlier version called "Celestial Mechanics" that he helped spawn with UCLA buds was from 2005. About that project, the artists write:

At any given moment, there can be 30,000 manmade objects in the sky above us: Planes, helicopters, satellites, weather balloons, space debris, and other diverse technologies. They watch, they guide, they protect, they communicate, they transport, they predict, they look out into the stars. In less than 100 years, the deep blue has become a complex web of machinery.

Our lives are closely tied to these networks in the sky, but a disjunction has occurred between us and the aerial technologies we use every day. We rarely consider the hulking, physical machines that have now become core to our lifestyle. By not being aware of the hardware we use every day, we may also not be aware of the social, economic, cultural, and political importance of these technologies. By visualizing them, it may lead to a better understanding of the forces that are shaping our future.

Koblin's flight obsession has led to other renderings of the frenzied anthill above the clouds, including Atlanta and the Southwest. Even more are posted at his Flight Patterns page – check out the oil-black blobular version of his map. The guy's not content with tinkering around with just air travel, though. Worth a look is this video showing how Amsterdam residents send texts on New Year's Eve and a music video for Interpol, which features a ghostly light grid of New York City.